JPS5877345A - Optical multiplex picture transmission system - Google Patents

Abstract

PURPOSE:To attain a picture transmission system with high accuracy, by multiplexingly transmitting data signals and a lot of picture signals through the use of photocouplers for optical isolation. CONSTITUTION:Optical signals lambda1-lambdan of different wavelengths from each set and frequencies f1-fn are assigned to n-set of cameras A1-An, and an optical signal lambda0 of a different wavelength from the wavelengths assigned to the cameras is assigned to m-set of processors C1-Cm of a data transmission system. After analog signals for the cameras A1-An are modulated in the frequencies f1-fn assigned at modulation sections B1-Bn, the signals are converted into optical signals with the assigned optical signals lambda1-lambdan, transmitted to a demodulator 8 of a master station via a photocoupler 4, an optical transmission line 5, and an optical branching filter 12, for display. In the master station, the cameras A1-An are selected with a console 3. Data of the processors C1-Cm are carried on the optical signal lambda0 with the polling system and transmitted to a master station CPU1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical multiplex image transmission system, and particularly relates to an optical multiplex transmission system for images of a large number of plants, and a computer (hereinafter referred to as CPU)
FIG. 1 shows a conventional example of an optical multiplex image transmission system suitable for achieving good compatibility with signal transmission and information processing.

Select one camera from console 3 and camera 9At to A. The selection signal is sent to the optical switch transmitter 2.
1, it is converted to E10 and passed through the directional coupling unit 20 as an optical signal of λ1, and reaches the optical switch 14. The selection signal is.

The optical receiver 19 for the optical switch performs O/E conversion.

The optical switch control unit 18 determines which camera is selected based on the input selection signal, and operates the optical switch 14 based on the determination to switch the optical signal. The switched signal is converted into a 0/E signal by the optical receiver 13 via the directional coupler 20 as a λ2 optical signal 1, then sent to the television 2.
will be displayed. 81 to B are modulation units. In the case of this system, cameras A, ~A, and modulation units 81~
In addition to B, the optical switch 14, optical switch control section 18, etc. must be installed at a site in the plant separate from the operation room, which often makes maintenance difficult.

In particular, when used in an atomic coupler, the optical switch 14 and the optical switch control section 18 are installed at the site of the plant.
That is, it must be installed in a radioactive environment, and maintenance and inspection during operation of the atomic couplant is difficult. Also,
Light has low reliability, so the 9° maintenance cycle is short.

On the other hand, there is a method for transmitting and receiving facsimile signals, television camera video No. 1, etc. as digital serial signals on the optical highway, but it requires a high frequency to transmit a large number of images, so the hardware is large. There is a problem with reliability. This is a major drawback, especially in cases where maintainability is important in the field, such as in nuclear power plants.

In addition, this type of optical highway usually has a loop configuration,
Since it has relay expansion, bypass in case of station failure, switch, etc., there is a drawback that reliability is reduced accordingly.

An object of the present invention is to provide an optical multiplex image transmission system that is easy to maintain and inspect.

The key point of the present invention is to optically insulate the CPU signal and image signal from each other using the same cable using an optical data cable, transmit the signal to the operation room using an optical coupler, take out the signal from the series loop using an optical splitter, and There is a switch etc. that performs light discrimination. That is, since neither the optical coupler nor the optical splitter operates mechanically or electrically, reliability is high. Furthermore, optical insulation makes it difficult for failures to spread. In addition, maintenance is easy because the optical switch and the like are installed in the operation room.

The signal of each CPU and the image signal of each camera have a wavelength of light λ.
. ~λ3 are assigned, and the former is a digital signal, and the latter is an analog signal with carrier frequencies f0~f1. Assign.

Therefore, a high bit rate is not required as a digital signal, and since the analog signal is transmitted in tt, the electrical hardware is relatively small. That is, the reliability of on-site equipment can be increased.

In addition, the TV in the control room has image memory!
D. It utilizes the information processing ability of the CPU to edit and record images.

FIG. 2 shows an optical multiplex image transmission system which is a preferred embodiment of the present invention. Each of the n cameras 6A1 to 6A8 has a different wavelength (λ1.λ1...λ,) and frequency (,
”, f:j,...f,) and h<.

The analog signals are subjected to B10 conversion in the modulation sections B, . The console 3 specifies one of the cameras A1-person. Based on this designation, an optical signal with a provisional wavelength transmitted through the optical transmission line (optical cable) 5 is selected and sent to the demodulator 8 via the optical splitter 12. /E conversion and display on TV 2.

FIG. 3 shows details of the modulator B, and FIG. 4 shows details of the demodulator 8. The analog signal from the camera is modulated by a carrier frequency f1 of a modulator 11, and B10 converted into light of wavelength λ1 by an optical transmitter 10. The selection signal from the console 3 causes the display control section 23 to drive the light switch 14 to select a predetermined light rod 16.

The optical signal selected by this operation is sent from the demultiplexer 15 to the optical receiver 13. The optical receiver 13 performs O/E conversion on this optical signal, distinguishes the electrical frequency, and displays it on the television 2. Furthermore, when there is a request for image storage from the console 3, the image is stored in the pixel memory 24, and when there is a request for screen correction, superimposition, etc., it is displayed in the 1-pixel memory 24 on the television 2.

do. As a result, the plan that will be transmitted at the actual site □
Images can be edited on the screen using the information processing capability of the CPU 1 of the master station of the data transmission system.

- It is also possible to record this edited screen by copying it to another page.

This function makes it possible to superimpose and record various types of information in one set when an abnormality occurs at a plant site.

FIG. 5 shows the spectrum of light transmitted within the optical transmission line 5. Data transmission between the CPU of the master station and the processing devices C of the plurality of slave stations is performed at a wavelength λ. PCM transmission is performed using the light. This is usually done using a polling method. This data-transmitted signal includes a signal indicating the originating or receiving slave station.

On the other hand, a wavelength of 11 to λ is used for the image signal.

Although they are transmitted as AM signals, they have different wavelengths, so they do not interfere with each other.

Further, FIG. 6 shows the spectrum of the image electrical signal. f
8-f, Fl, for example, correspond to the respective frequencies of a general home television channel, so they do not interfere with each other. Since these f1 to f are further modulated by the optical signals λ, to λ, the number of optical image signals transmitted in the optical transmission line 5 is n
It becomes xn.

According to the present invention, by installing a large node such as an optical switch on the operating rope, maintenance and inspection can be easily performed, and the failure rate of equipment installed on site can be reduced. This has the effect of significantly shortening the average maintenance time on site. In particular, when the present invention is applied to an atomic coupler, large hardware such as optical switches can be placed in an operation room with a non-radioactive environment, thereby reducing the number of devices in an optical multiplex image transmission system placed at the plant site. Since the pressure can be kept to a minimum, maintenance and inspection become significantly easier. Furthermore, since each television camera is optically insulated, failures do not adversely affect other optical transmissions, and can be left alone if the system is less affected.

In addition, data transmission and image transmission between the master station and slave stations can be performed using a single optical transmission line, which simplifies the information transmission system of the plant.

Furthermore, since the information processing capability of the CPU of the master station can be applied to plant images, advanced plant monitoring functions such as image editing processing can be realized.

[Brief explanation of the drawing]

Figure 1 is a system diagram of a conventional optical multiplex image transmission system;
The figure is a system diagram of the optical multiplexing image transmission system of the present invention, and FIG. 3 is a configuration diagram of the modulation section shown in FIG. 2. Fig. 4 is a block diagram of the demodulation section shown in Fig. 2, and Fig. 5 is an explanation sole showing the spectrum of light in the optical transmission line.
... Optical coupler, 5... Optical transmission line, A... Camera, B
. . . Modulation section, 8 . . . Demodulation section, 10. . . Optical transmitter. 11... Modulator, 12... Optical splitter %13... Optical receiver, 14... Optical switch, 15... Optical splitter,
16... Optical rod, 18... Optical switch control section, 1
9... Optical receiver for optical switch %20... Directional coupling unit, 21... Optical transmitter for optical switch, C... Processing device, 23... Display control unit, 24... pixel memory. 3rd eye 4th country

Claims (1)

[Claims] 1. A plurality of slave stations located at a plant installation location. a master station installed in an operation room; an optical signal transmission path connecting the master station and each of the slave stations; a plurality of television cameras arranged at the plant installation location; means for converting an image taken by the user into an optical signal and transmitting the image to the optical signal transmission line; means for selecting the television camera and the camera located in the operation room; and a television camera located at the writer i for selection. means for extracting the optical signal of the image from the optical signal transmission line and converting it into an electric signal; and means for displaying the signal from the selected television camera arranged in the operation room and converted into an electric signal. An optical multiplex image transmission system consisting of: